The Neural Bases of Statistical and Referential Cues to Phonetic Category Structu

描述（申请人提供）：本研究的目的是调查成年人获得新语音类别能力的神经机制。具体来说，我们将研究如何与输入的统计和参考属性的形状受试者的感知灵敏度项目沿着一个声学语音连续体，以及这些敏感性的变化的神经相关的经验。这将通过使用功能性MRI（fMRI）来测量已熟悉来自非母语语音连续体的听觉刺激的成年受试者的激活模式来实现。重要的是，在熟悉过程中呈现的听觉刺激的统计分布，以及伴随听觉刺激的视觉/参考线索将是不同的，以隔离语音类别身份的统计和参考线索的神经相关性。神经结构的敏感性相当于声学间隔在不同的位置沿着连续使用短时间间隔习惯化范式，其中释放适应的fMR信号被用作标记神经敏感性的变化，语音类别结构进行了探讨。有人认为，激活的变化作为熟悉的功能，如后上级颞回等领域将表明，语音类别结构的变化是介导的语音处理流的早期。另外，额叶（额下回）和顶叶（缘上回、角回）结构的激活变化表明，语音类别的扭曲发生在加工流的后期，反映了注意力、词汇或执行系统的招募。结果将揭示的过程中，统计和参考线索形状的感知灵敏度，最终形成的语音类别的基础。 相关性：这项拟议的研究将揭示语音类别习得的神经机制，并最终可能用于为患有发育性语言障碍的儿童提供治疗策略。此外，结果应该增加我们对成人语音处理的神经基础的理解，这可能用于建议失语症患者因脑损伤而遭受语言障碍的康复策略。

DESCRIPTION (provided by applicant): The goal of this research is to investigate the neural mechanisms which underlie adults' ability to acquire new phonetic categories. Specifically, we will investigate how experience with statistical and referential properties of the input shapes subjects' perceptual sensitivities to items along an acoustic-phonetic continuum, and the neural correlates of these changes in sensitivity. This will be accomplished by using functional MRI (fMRI) to measure activation patterns in adult subjects who have been familiarized with auditory stimuli taken from a non-native phonetic continuum. Importantly, the statistical distribution of the auditory stimuli presented during familiarization, as well as the visual/referential cues which accompany the auditory stimuli will be varied in order to isolate neural correlates of statistical and referential cues to phonetic category identity. Sensitivity of neural structures to equivalent acoustic intervals at different locations along the continuum will be probed using a short-interval habituation paradigm, in which release from adaptation of the fMR signal is used as a marker for neural sensitivity to changes in phonetic category structure. It is argued that changes in activation as a function of familiarization in such areas as the posterior superior temporal gyrus would suggest that the changes in phonetic category structure are mediated early in the phonetic processing stream. Alternatively, changes in activation in the frontal (inferior frontal gyrus) and parietal (supramarginal gyrus, angular gyrus) structures would suggest that the warping of phonetic categories occurs later in the processing stream and reflects the recruitment of attentional, lexical, or executive systems. Results will shed light on the process by which statistical and referential cues shape perceptual sensitivities which ultimately form the basis of phonetic categories. Relevance: The proposed research will shed light on the neural mechanisms which underlie the acquisition of phonetic categories, and may ultimately be used to inform treatment strategies for children with developmental language disorders. Additionally, results should add to our understanding of the neural bases of speech processing in adults, which may be used to suggest rehabilitative strategies for aphasic patients who have suffered language impairments due brain injury.